As a main content of the high-temperature purification technology, high temperature dust removal technology is not only the key of the development of the current IGCC power generation technology and PFBC power generation technology but also particularly important to the development of the more advanced coal-fired combined cycle power generation technology. In addition, it is also widely applied in chemistry industry where many high temperature gases used as either desiccation or heating media must be purified.
Researchers have studied the high-temperature purification technology since 1970s. Generally speaking, owing to the earlier researches, some developed countries, including the United States, Germany, Japan, the United Kingdom and the Netherlands, are in the leading position of this technology.
To date, the high-temperature dust removing technology mainly includes: electrostatic precipitation, cyclone, ceramic filter, metal felt filter and moving granular bed filter. An electrostatic precipitator (ESP) is characterized as low pressure drop loss, no clogging, large amount of flue gas purification and high collection efficiency especially in the part of the fine particle collection. Traditional ESPs are corona electrostatic dust collectors which are based on the high-voltage corona discharge. In the high-temperature ambience, corona phenomenon is difficult to maintain due to its corona running in a small voltage range and electrical insulation problems is hard to solve because of its high operating voltage (up to 50-100 KV). As a result, A traditional ESP is fit to be used in the low-temperature ambience of less than 450° C. This invention, a kind of no corona electrostatic precipitation, based on the thermal electron emission, has good prospects of development and extensive application prospects in the field of high-temperature flue gas clean up.